The present invention relates to alkylsulfonamido heterocyclic compounds which are thrombin inhibitors and thus useful in inhibiting formation of thrombi.
U.S. application Ser. No. 146,714 filed Nov. 10, 1993, discloses sulfonamido heterocyclic thrombin inhibitors of the invention have the structure 
wherein G is an amido moiety which is 
including all stereoisomers thereof; and including all pharmaceutically acceptable salts thereof; wherein
R is hydrogen, hydroxyalkyl, aminoalkyl, amidoalkyl, alkyl, cycloalkyl, aryl, arylalkyl, alkenyl, alkynyl, arylalkoxyalkyl, or an amino acid side chain, either protected or unprotected;
R1 and R2 are independently hydrogen, lower alkyl, cycloalkyl, aryl, hydroxy, alkoxy, oxo, thioxo thioalkyl, thioaryl, amino or alkylamino; or R1 and R2 together with the carbons to which they are attached form a cycloalkyl, aryl, or heteroaryl ring; and
R3 is lower alkyl, aryl, arylalkyl, heteroaryl, quinolinyl or tetrahydroquinolinyl;
n is 0, 1 or 2;
m is 0, 1, 2 or 3;
Y is NH or S;
p is 0, 1 or 2;
Q is a single bond or 
A is aryl or cycloalkyl, or an azacycloalkyl ring
A of 4 to 8 carbons in the ring or an azaheteroalkyl ring a of 4 to 8 carbons in the ring, A 
xe2x80x83where
X is CH2, O, S or NH;
q is 0, 1, 2, 3 or 4 if x is CH2;
q is 2, 3 or 4 if X is O, S or NH;
Y1 and Y2 are independently H, lower alkyl, halo or keto; and
R4 is guanidine, amidine or aminomethyl;
where A is aryl or cycloalkyl, R4 is guanidine, amidine or aminomethyl;
where A is azacycloalkyl or azaheteroalkyl, R4 is amidine;
provided that where X is a hetero atom (that is, A is azaheteroalkyl), then there must be at least a 2-carbon chain between X and any N atom in the ring A or outside ring A;
and provided that where G is Gl, then if R3 is alkyl, the alkyl must contain at least 3 carbons.
The alkylsulfonamido heterocyclic thrombin inhibitors of the invention have the structure I 
wherein G is an amido moiety which is 
including all stereoisomers thereof; and including all pharmaceutically acceptable salts thereof; wherein
R is hydrogen, hydroxyalkyl, aminoalkyl, amidoalkyl, alkyl, cycloalkyl, aryl, arylalkyl, alkenyl, alkynyl, arylalkoxyalkyl, or an amino acid side chain, either protected or unprotected;
R1 and R2 are independently hydrogen, lower alkyl, cycloalkyl, aryl, hydroxy, alkoxy, oxo, thioketal, thioalkyl, thioaryl, amino or alkylamino; or R1 and R2 together with the carbons to which they are attached form a cycloalkyl, aryl, or heteroaryl ring; and
n is 0, 1 or 2;
m is 0, 1, 2 or 3;
Y is NH or S; and
Alkyl1-2 is methyl or ethyl.
The term xe2x80x9clower alkylxe2x80x9d or xe2x80x9calkylxe2x80x9d as employed herein by itself or as part of another group includes both straight and branched chain radicals of up to 18 carbons, preferably 1 to 8 carbons, such as methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, pentyl, hexyl, isohexyl, heptyl, 4,4-dimethylpentyl, octyl, 2,2,4-trimethylpentyl, nonyl, decyl, undecyl, dodecyl, the various branched chain isomers thereof, and the like as well as such groups including 1, 2 or 3 halo substituents (for example, to form CF3 or CF3CH2) and/or 1 or 2 of the following substituents: an aryl substituent (for example, to form benzyl or phenethyl), an alkyl-aryl substituent, a haloaryl substituent, a cyclo-alkyl substituent, an alkylcycloalkyl substituent, an alkenyl substituent, an alkynyl substituent, hydroxy or a carboxy substituent. It will be appreciated that the same xe2x80x9calkylxe2x80x9d group may be substituted with one or more of any of the above substituents.
The term xe2x80x9ccycloalkylxe2x80x9d by itself or as part of another group includes saturated cyclic hydrocarbon groups containing 3 to 12 carbons, preferably 3 to 8 carbons, which include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl and cyclododecyl, any of which groups may be substituted with substituents such as halogen, lower alkyl, alkoxy and/or hydroxy groups.
The term xe2x80x9carylxe2x80x9d or xe2x80x9cArxe2x80x9d as employed herein by itself or as part of another group refers to mono-cyclic or bicyclic aromatic groups containing from 6 to 10 carbons in the ring portion, such as phenyl, or naphthyl. Aryl (or Ar), phenyl or naphthyl may include substituted aryl, substituted phenyl or substituted naphthyl, which may include 1 or 2 substituents on either the Ar, phenyl or naphthyl such as lower alkyl, cyano, amino, alkylamino, dialkylamino, nitro, carboxy, carboalkoxy, trifluoromethyl, halogen (Cl, Br, I or F), lower alkoxy, arylalkoxy, hydroxy, alkylthio, alkylsulfinyl, alkylsulfonyl, arylthio, arylsulfinyl and/or arylsulfonyl.
The term xe2x80x9caralkylxe2x80x9d, xe2x80x9caryl-alkylxe2x80x9d or xe2x80x9caryl-lower alkylxe2x80x9d as used herein by itself or as part of another group refers to lower alkyl groups as discussed above having an aryl substituent, such as benzyl.
The term xe2x80x9clower alkoxyxe2x80x9d, xe2x80x9calkoxyxe2x80x9d or aralkoxyxe2x80x9d includes any of the above lower alkyl, alkyl or aralkyl groups linked to an oxygen atom.
The term xe2x80x9chalogenxe2x80x9d or xe2x80x9chaloxe2x80x9d as used herein by itself or as part of another group refers to chlorine, bromine, fluorine or iodine with chlorine being preferred.
The term xe2x80x9clower alkenylxe2x80x9d or xe2x80x9calkenylxe2x80x9d as employed herein by itself or as part of another group includes a carbon chain of up to 16 carbons, preferably 3 to 10 carbons, containing one double bond which will be separated from xe2x80x9cNxe2x80x9d by at least one saturated carbon moiety such as xe2x80x94(CH2)qxe2x80x94 where q can be 1 to 14, such as 2-propenyl, 2-butenyl, 3-butenyl, 2-pentenyl, 4-pentenyl and the like, and may include a halogen substituent such as I, Cl, or F.
The term xe2x80x9clower alkynylxe2x80x9d or xe2x80x9calkynylxe2x80x9d as employed herein by itself or as part of another group includes a carbon chain of up to 16 carbons, preferably 3 to 10 carbons, containing one triple bond which will be separated from xe2x80x9cNxe2x80x9d by at least one saturated carbon moiety such as xe2x80x94(CH2)qxe2x80x2xe2x80x94 where qxe2x80x2 can be 1 to 14, such as 2-propynyl, 2-butynyl, 3-butynyl and the like.
The term xe2x80x9cheteroarylxe2x80x9d or heteroaromatic by itself or as part of another group refers to a 5-10-membered aromatic ring which includes 1, 2, 3 or 4 hetero atoms such as nitrogen, oxygen or sulfur, such as 
and the like. The heteroaryl rings may optionally be fused to aryl rings defined previously. The heteroaryl rings may optionally include 1 or 2 substituents such as halogen (Cl, Br, F or CF3), lower alkyl, lower alkoxy, carboxy, amino, lower alkylamino and/or dilower alkylamino.
The term xe2x80x9camino acid side chainxe2x80x9d refers to any of the known alpha-amino acids such as arginine, histidine, alanine, glycine, lysine, glutamine, leucine, valine, serine, homoserine, allothreonine, naphthylalanine, isoleucine, phenylalanine and the like.
Preferred are compounds of formula I wherein n is 0 or 1; m is 2; Alkyl1-2 is methyl; R is arylalkyl; R1 and R2 are independently hydrogen or lower alkyl such as methyl or ethyl; and Y is xe2x80x94NHxe2x80x94.
The compounds of formula I of the invention wherein Y is NH may be prepared according to the following Reaction Sequence I. 
The compounds of formula I of the invention wherein Y is NH may also be prepared according to the following Reaction Sequence II 
As seen in the above Reaction Sequence I, compounds of formula I wherein Y is xe2x80x94NHxe2x80x94, are prepared as follows. The ester II is made to undergo a carbodiimide coupling reaction with protected amino acid III in the presence of ethyl 3-(3-dimethylamino)propyl carbodiimide hydrochloride (WSC) or dicyclohexylcarbodiimide (DCC), and 1-hydroxybenzotriazole monohydrate (HOBT), and N-methylmorpholine (NMM), and in the presence of an inert organic solvent such as dimethylformamide (DMF), THF or N-methylpyrrolidone, to form the amide IV. Amide IV is deprotected by treatment with trifluoroacetic acid with or without the presence of dry inert organic solvent such as dichloromethane, chloroform or THF at temperatures within the range of from about xe2x88x9215xc2x0 to about 20xc2x0 C. Sulfonyl chloride V is added followed by organic base such as triethylamine, pyridine or N,N-diisopropylethylamine to form the sulfonamide VI. Sulfonamide VI is hydrolyzed by treatment with alkali metal base such as NaOH or LiOH in the presence of an alcohol solvent such as methanol or ethanol. The reaction mixture is acidified with HCl, KHSO4 or H2SO4, to form acid VII. The acid VII is then subjected to a carbodiimide coupling reaction wherein VII is treated with protected amine VIII in the presence of WSC or DCC, and HOBT, and NMM, in the presence of an inert organic solvent such as dimethylformamide, THF or N-methylpyrrolidone, to form sulfonamide IX. The sulfonamide IX is then dissolved in an alcohol solvent such as ethanol or methanol, to which HCl has been added and the mixture is hydrogenated over Pdxe2x80x94C or Pd(OH)2xe2x80x94C in the case where P1 is carbobenzyloxy. The product is then treated with amidine sulfonic acid X in the presence of an alcohol solvent such as ethanol to form the compound of the invention IA.
As seen in the above Reaction Sequence II, compounds of formula I wherein Y is xe2x80x94NHxe2x80x94, are also prepared as follows. The protected acid IIA is made to undergo a carbodiimide coupling reaction with protected diamine VIII in the presence of ethyl 3-(3-dimethylamino)propyl carbodiimide hydrochloride (WSC) or dicyclohexylcarbodiimide (DCC), and 1-hydroxybenzotriazole monohydrate (HOBT), and N-methylmorpholine (NMM), and in the presence of an inert organic solvent such as dimethylformamide (DMF), THF or N-methylpyrrolidone, to form the amide IXA. Amide IXA is deprotected by treatment with trifluoroacetic acid (TFA) when P is t-butoxycarbonyl (BOC) or H2xe2x80x94Pd/C when P is carbobenzyloxy (CBz), with or without the presence of dry inert organic solvent such as dichloromethane, chloroform or THF, at temperatures within the range of from about xe2x88x9215xc2x0 to about 20xc2x0 C. to form amide IXB. The amide IXB is then subjected to a carbodiimide coupling reaction wherein IXB is treated with protected amine III in the presence of WSC or DCC, and HOBT, and NMM, in the presence of an inert organic solvent such as dimethylformamide, THF or N-methylpyrrolidone, to form amide IXC. The amide IXC is then dissolved in an alcohol solvent such as ethanol or methanol, to which HCl has been added and the mixture is hydrogenated over Pdxe2x80x94C or Pd(OH)2xe2x80x94C in the case where P1 is CBz or treated with trifluoroacetic acid when P1 is BOC. The product is then treated with amidine sulfonic acid X in the presence of an alcohol solvent such as ethanol to form IXD. Compound IXD is deprotected by treatment with TFA when P is BOC or by treatment with H2xe2x80x94Pd/C when P is CBz, as described above, and sulfonyl chloride V is added followed by organic base such as triethyl-amine, pyridine or N,N-diisopropylethylamine to form the sulfonamide IA.
The compounds of formula I of the invention wherein Y is S may be prepared according to the following Reaction Sequence III. 
Referring to the above Reaction Sequence III, compounds of formula I wherein Yxe2x95x90S can be prepared as follows. The acid VII is subjected to a carbodiimide coupling reaction wherein VII is treated with an aminoalcohol XI in the presence of WSC or DCC, HOBT, and NMM, in the presence of an inert organic solvent such as dimethylformamide, THF or N-methylpyrrolidone, to form sulfonamide alcohol XII. The sulfonamide alcohol XII is reacted with p-toluenesulfonyl chloride (TsCl) in pyridine, or in a solvent such as methylene chloride or chloroform, with N,N-dimethylaminopyridine to provide toluenesulfonate XIII. The compound IB (Yxe2x95x90S) is prepared by treating XIII with thiourea in a solvent such as DMF or DMSO at temperatures within the range of from about 25xc2x0 C. to about 100xc2x0 C.
The compounds of formula I of the invention can be obtained as pharmaceutically acceptable acid addition salts by reacting a free base with an acid, such as hydrochloric, hydrobromic, hydroiodic, nitric, sulfuric, phosphoric, acetic, citric, maleic, succinic, lactic, tartaric, gluconic, benzoic, methanesulfonic, ethanesulfonic, benzenesulfonic, p-toluenesulfonic acid or the like.
The compounds of the present invention are serine protease inhibitors, and in particular may inhibit thrombin, Factor Xa, and/or trypsin. The compounds of the present invention are useful for the treatment or prophylaxis of those processes which involve the production and/or action of thrombin. This includes a number of thrombotic and prothrombotic states in which the coagulation cascade is activated which include, but are not limited to, deep vein thrombosis (DVT), disseminated intravascular coagulopathy (DIC), Kasabach-Merritt syndrome, pulmonary embolism, myocardial infarction, stroke, thromboembolic complications of surgery (such as hip replacement and endarterectomy) and peripheral arterial occlusion. In addition to its effects on the coagulation process, thrombin has been shown to activate a large number of cells (such as neutrophils, fibroblasts, endothelial cells, smooth muscle cells). Therefore, the compounds of the present invention may also be useful for the treatment or prophylaxis of adult respiratory distress syndrome, septic shock, septicemia, inflammatory responses which include, but are not limited to, edema, acute or chronic atherosclerosis, and reperfusion damage.
The compounds of the invention may also be useful in treating neoplasia/metastasis (in particular those which utilize fibrin) and neurodegenerative diseases such as Alzheimer""s disease and Parkinson""s disease. In addition, the compounds of the present invention may be useful to prevent restenosis following arterial injury induced by endogenous (rupture of an atherosclerotic plaque) or exogenous (invasive cardiological procedure) events.
The compounds of the present invention may also be used as an anticoagulant in extracorpeal blood circuits, such as those necessary in dialysis and surgery (such as coronary artery bypass surgery).
The compounds of the present invention may also be used in combination with thrombolytic agents, such as tissue plasminogen activator (natural or recombinant), streptokinse, urokinase, prourokinase, anisolated streptokinase plasminogen activator complex (ASPAC), animal salivary gland plasminogen activators, and the like. The compounds of the present invention may act in a synergistic fashion to prevent reocclusion following a successful thrombolytic therapy and/or reduce the time to reperfusion. The compounds of the present invention may also allow for reduced doses of the thrombolytic agent to be used and therefore minimize potential hemorrhagic side-effects.
The compounds of the present invention may also be used in combination with other antithrombotic or anticoagulant drugs such as thromboxane receptor antagonists, prostacyclin mimetics, phosphodiesterase inhibitors, fibrinogen antagonists, and the like.
Compounds of the present invention that inhibit trypsin may also be useful for the treatment of pancreatitis.
The compounds of the invention can be administered orally or parenterally to various mammalian species known to be subject to such maladies, e.g., humans, cats, dogs and the like in an effective amount within the dosage range of about 0.1 to about 100 mg/kg, preferably about 0.2 to about 50 mg/kg and more preferably about 0.5 to about 25 mg/kg (or from about 1 to about 2500 mg, preferably from about 5 to about 2000 mg) on a regimen in single or 2 to 4 divided daily doses.
The active substance can be utilized in a composition such as tablet, capsule, solution or suspension containing about 5 to about 500 mg per unit of dosage of a compound or mixture of compounds of formula I. They may be compounded in conventional matter with a physiologically acceptable vehicle or carrier, excipient, binder, preservative, stabilizer, flavor, etc., as called for by accepted pharmaceutical practice.